Yarn folding mechanism

ABSTRACT

The yarn folding mechanism includes a pair of wires extended across a plurality of strands of yarn between two opposing surfaces, the wires being connected at each end to a rotationally movable member capable of moving the wires along separate, concentric, orbital paths. The orbital movement at the ends of the wires is translated into linear movement where the wires engage and fold the yarn by a cam surface that engages and guides the wires along their separate linear paths. The wires are connected at their ends to a coil spring so that the length of the wire between the members can vary, all the time maintaining a minimum tension in the wires. Each member is rotated by a reversible stepping motor that is programmed to move its wire along a predetermined orbital path.

Elite Abel States aten [191 [4 1 Oct. 28, 1975 [73] Assignee: Permalock Company, Inc., Auburn Heights, Mich.

[22] Filed: Jan. 15, 1973 [21] Appl. No.: 323,440

[52] U.S. Cl. 156/435 [51] Int. Cl. B04H 11/04 [58] Field of Search 156/435, 368, 72, 439,

3,790,426 2/1974 Byluno 156/435 Primary Exam'iner-Douglas J. Drummond Assistant Examiner-J. J. Gallagher Attorney, Agent, or FirmLane, Aitken, Dunner & Zeims [57] ABSTRACT The yarn folding mechanism includes a pair of wires extended across a plurality of strands of yarn between two opposing surfaces, the wires being connected at each end to a rotationally movable member capable of moving the wires along separate, concentric, orbital paths. The orbital movement at the ends of the wires is translated into linear movement where the wires engage and fold the yarn by a cam surface that engages and guides the wires along their separate linear paths. The wires are connected at their ends to a coil spring so that the length of the wire between the members can vary, all the time maintaining a minimum tension in the wires. Each member is rotated by a reversible stepping motor that is programmed to move its wire along a predetermined orbital path.

38 Claims, 25 Drawing Figures US. Patent Oct. 28, 1975 Sheet 2 of6 3,915,789

US; Patent Oct.28,1'975 Sheet3of6 3,915,789

FIG/2.

US. Patent Oct. 28, 1975 Sheet4 of6 3,915,789

FIG/3.

res

US. Patent Oct.28, 1975 Sheet5of6 3,915,789

US. Patent 0a. 28, 1975 sheei 6 of 6 3,915,789

MNGE YARN FOLDING MECHANISM BACKGROUND OF THE INVENTION This invention relates to machines for making nonwoven bonded carpeting and, more particularly, to the portion of such a machine that folds the yarn from which the pile is formed and either plants the yarn in the bonding material in which it is anchored or arranges the yam so that the bonding material can be applied later.

Machines have been developed for making carpeting by folding a number of strands of yarn in a row simultaneously and planting them in a layer of adhesive spread across the surface of a sheet of backing material, and then repeating the operation on an opposing parallel sheet of backing material. This is done to form a series of accordion-type loops from each strand of yarn between the backing layers. After the adhesive has been cured, the loops are severed midway between the backing layers to form two separate carpets.

Another type of machine has been developed in which the loops of yarn are formed initially without bonding them to the backing layers, and the adhesive is applied later to the yarn. In both types of machines the adhesive can be used as the backing layer in addition to being the means for anchoring the yarn in place.

When a backing material is used, it is normally formed of woven strands of jute, although there are many other suitable types of backing material. The bonding material can be an adhesive such as a liquid synthetic resin which has been applied to the backing sheets or directly to the yarn. Polyvinylchloride (PVC) has been found to be effective.

A number of different types of mechanisms have been developed for embedding the yarn into bonding material. As taught by US. Pat. No. 3,531,343 to Couquet, individual strands of yarn can be planted oneby-one into an advancing sheetof backing material coated with an adhesive. The lower end of each strand is clamped and cut the desired length. The severed portion is then lowered by the clamping apparatus and planted into the adhesive. This system for manufacturing nonwoven carpeting is disadvantageous for several reasons. First, because each individual strand has to be clamped, severed and lowered into place, much time is wasted by separately performing each one of these steps. In addition, because of the space taken up by the clamping mechanism and other elements used in the planting process, there is a physical limitation upon the number of strands that can be planted per square inch, thereby limiting the gauge of the carpet pile.

Several machines have been developed which use blade-like members that extend across the entire width of the sheet of backing material for folding the strands of yarn and pushing them into an adhesive layer. One such machine is shown in US. Pat. No. 3,127,293 to Trenteseaux, which provides a blade and a series of superimposed plates for alternately urging the strands of yarn against adhesive that is coated on a pair of backing strips at a point near the top of the well into which the backing layers are advanced. A pair of metal foils is provided for cooperating with the blade and plates so that the strands of yarn are folded in a way to prevent an excessive length of the yarns from becoming embedded in the adhesive layer. However, problems arose with this machine because it proved to be too slow since each member that presses against the strands of I yarn must be completely withdrawn before the other member can be moved into place to form the next loops of the accordion-type chains. In addition, the operation of the machine is such that the members tended to become coated with the adhesive and had to be cleaned periodically, thereby necessitating closing down the machine and stopping production.

Some of these problems were apparently solved by the machine in US. Pat. No. 3,657,052 to Debonnet, where a different mechanism that includes a pair of blades is provided for folding and planting the yarn. Each blade operates to hold the yarn in position in the adhesive for a short time while the second blade moves toward its bonding position so that the yarns will not be pulled out of the adhesive. This delaying action is accomplished by means of cam surfaces which operate to retract the blades along paths different from those along which they were advanced. However, although this mechanism is an apparent improvement over the one in the Trenteseaux patent, the blade that holds the planted yarns in place is not delayed long enough, which results in some of the yarns being pulled out of the adhesive during the next planting step. In addition, the blades and their movement require highly complex equipment that includes a number of heavy, expensive and space-consuming components. Much energy is required to operate the machine which is extremely expensive to manufacture and operate. Because of the large number of moving parts and their relatively large size, the machine is limited in its operational speed.

SUMMARY OF THE INVENTION In accordance with the invention, a mechanism for folding and planting strands of yarn is provided which solves the problems discussed above.

In place of the heavy, bulky blades used in prior art devices, a pair of tensioned wires are manipulated to fold and plant the strands of yarn. The wires extend across the strands of yarn and are connected at their corresponding ends to a pair of rotatably movable wire holders, one nested within the other so that the wires can be moved independent of each other along separate, concentric, orbital paths. A cam profile plate is located between the wire holders and the yarn, the plate including a rectangular opening defined by a cam surface that the wires engage for translating the orbital movement of the portions of the wires connected to the wire holders to linear movement to effect the folding and planting of the strands of yarn.

The wire holders are rotated by means of a pair of conventional, reversible stepping motors that are programmed to operate in accordance with the sequence that will be described in detail below.

By providing a pair of wires instead of the blades, all of the bulky mechanical components located above the blades to move them are eliminated. Since the wires are much lighter than the blades, they are much more responsive to movement and can fold and plant the yarns much quicker than the prior art devices. The path along which each wire moves can be set so that the planted yarns are held in place by the wires longer than in prior art machines. The movement of the wires can be controlled precisely enough that the yarns can be planted sufficiently without the wires themselves contacting the adhesive.

In addition, because much less energy is consumed due to the lightweight nature of the wires and the mechanism for moving them, operating costs are significantly reduced. Because of the much simpler moving mechanism, the carpet making machine is significantly less expensive to manufacture and easier to maintain and repair after put into operation.

BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of the invention, reference may be had to the following description of an exemplary embodiment of the invention taken in conjunction with the accompanying drawings in which:

FIG. 1 is a front view, partially in section, of the portion of the carpet making machine where the layers of backing material are advanced and coated with adhesive, the yarn is folded and planted in the adhesive and the adhesive is cured,

FIG. 2 is a plan view of the portion of the machine mounted on the portion shown in FIG. 1 (if one view is rotated 90 in the horizontal plane) which operates the wires that fold and plant the strands of yarn;

FIG. 3 is an exaggerated sectional view of one of the wires planting a strand of yarn in the adhesive coating on a layer of backing material;

FIGS. 4l2 are schematic views of the wires moving through one folding and planting cycle;

FIG. 13 is a plan view on one side of the machine of the mechanism that moves the wires;

FIG. 14 is a plan view of the cam profile plate that translates the orbital movement of the wires into linear movement;

FIG. 15 is a sectional view of the cam profile plate looking in the direction of the line 15-15 as shown in FIG. 14;

FIGS. 16-24 are schematic views showing the compara'tive positions of the wires as they move along their orbital and linear paths into the positions shown in FIGS. 4-12, respectively;

FIG. 25 is a sectional view of the wire holders that move the wires along their orbital paths.

DETAILED DESCRIPTION OF AN EXEMPLARY EMBODIMENT An exemplary embodiment of the yarn folding mechanism will now be described in detail. This embodiment is described in conjunction with a machine for making nonwoven carpet. This machine, as shown in FIG. 1, continuously advances two layers of backing material 10, which are unwound from the rolls 12. The backing layers 10 are advanced by the driving roller 14 and the pressure roller 16. Adjustable stepping motors (not shown) are used to drive the pressure rollers 16 so that the layers of backing material 10 are advanced in steplike fashion for reasons which will become apparent below. The stepping motors are synchronized with each other so that both layers of backing material 10 will be advanced at exactly the same speed and between the same intervals.

The rollers 14, 16, advance the layers of backing material 10 across the guides 18 which include a flat horizontal surface integral with a flat vertical surface, the vertical surfaces facing each other to form a well 20 between them. As the layers of backing material 10 move across the horizontal surfaces of the guides 18, a layer of adhesive such as polyvinylchloride (PVC) is applied to the outer surfaces of the layers 10. The PVC can be applied directly from a reservoir (not shown), a plurality of nozzles (not shown) or a perforated tube 22 which extends across the entire width of the layers of backing material 10. This latter means for applying the PVC is described in greater detail in my co-pending application mentioned above.

As the layers of backing material 10 coated with the PVC advance into the well 20, the strands of yarn 24 extending in a row across the width of the backing layers 10 are bonded in accordion-like fashion between the opposing layers of backing material 10. The mechanism which performs the folding and planting operation prior to bonding is the subject of this invention and will be described in detail below. After the layers of backing material 10 have been connected by the accordionlike chains of yarn, they move into an oven 26 where heat is applied by any suitable heating means (not shown) for curing the PVC and anchoring the yarn 24 in place. The connected layers of backing material 10 then move out of the oven 26 to a cutter (not shown) which severs the yarn 24 between the layers of backing material 10 to form two separate carpets.

Alternatively,, the mechanism can be used just to fold the strands of yarn to form the plurality of accordion-like chains, the PVC or other adhesive being applied later. figures the The mechanism used for folding and planting the strands of yarn 24 is generally shown in FIG. 2. This portion of the machine includes the mounting pads 28 which are positioned to be placed upon the mounting pads 30 on the portion of the machine shown in FIG. 1, the two FIGS. coinciding if one of them is rotated in the horizontal plane. These two portions of the machine are designed so that when the mounting pads 28, 30, are properly aligned, the upper portion of the machine shown in FIG. 2 will be in position to perform the folding and planting operation which will now be described in detail.

The folding and planting of the strands of yarn 24 are accomplished by means of a pair of wires 32, 34, which engage the yarn 24 for alternately pushing the strands of yarn 24 into the PVC on one layer of backing material 10 and then into the PVC on the other layer of backing material 10. The planting takes place a short distance below the upper edge of the well 20.

Each of the wires 32, 34, is tensioned between a pair of wire holders which are mounted for movement along with their moving means in the housings 36, all of which will be described in detail below. The wires both extend across the entire width of the layers of backing material 10 and can be formed of stainless steel and have a diameter of about U 16th of an inch.

The housings 36 are connected to the machine through the braces 38 which are attached to the vertical support members 40. As will be described in greater detail below, the wire holders move the end portions of the wires 32, 34, through separate, concentric, orbital paths. This orbital movement is then translated into linear movement so that the wires can fold the strands of yarn 24 and plant them in the PVC on the advancing layers of backing material 10.

As shown in exaggerated fashion in FIG. 3, the layers of backing material 10, coated with PVC, move horizontally along the guide plates 18 and then vertically into the well 20, in the direction of the arrow. At a short distance below the upper edge of the well 20, the wires 32, 34, push the strands of yarn 24 into the PVC coating. The machine can be adjusted precisely enough so that the wires 32, 34, push the folded ends of the strands of yarn 24 into the PVC a distance sufficient to effect the planting of the strands of yarn without themselves entering the PVC layer. In this way, the wires 32, 34, never come in contact with the PVC and remain clean. The paths along which the portions of the wires 32, 34, that engage the yarn travel will now be described in connection with FIGS. 4-12, the detail in FIG. 3 being eliminated for ease of understanding.

The wire 32 is shown as being solid and the wire 34 hollow so that they can be followed easily, although in reality both wires would normally be solid; The lines 42 designate the combination of the guide plates 18 over which the layers of the backing material coated with the PVC are advancing step-by-step. The numbers along the vertical portions of the lines 42 indicate the positions where the strands of yarn 24 are planted in the PVC coated layers of backing material 10 while they are stopped between each incremental'step during the continuous intermittent advancement. I

Referring now to FIG. 4, the loop located at Step 1 on the left-hand side of the well 20 has already been planted in the layer of backing material 10. While the layers of backing material 10 are stopped, the wire 32 pushes the strands of yarn 24 into the PVC on the layer of backing material 10 at Step 2 on the right-hand side of the well 20. While the wire 32 is in the position shown in FIG. 4, the wire 34 is poised and ready to push the yarn 24 into the PVC on the left-hand side of the well 20 after the backing layers 10 advance and are stopped again. After the wire 32 has moved from the position shown in FIG. 4 to the position shown in FIG. 5 to be out of the way of the wire 34 and the yarn 24, the comb 44, shown in FIG. 2, then clamps the strands of yarn 24 and drops them a predetermined distance to create slack in the yarn 24 to enable the yarn 24 to be planted on the left-hand side of the well 20 at Step 3 without pulling out the yarn already planted at the right-hand side of the well 20 at Step 2. This known clamping and dropping mechanism can be replaced by any suitable means that can be synchronized with the movement of the wires and backing material and operate as described. After the slack has been created, the wire 34 is moved from the position shown in FIG. 5, straight down to the position shown in FIG. 6.

The wire 34 is then moved to the left, from the position shown in FIG. 6 to the position shown in FIG. 7, to push the yarn 24 into the PVC on the layer of backing material 10 at the left-hand side of the well 20 at Step 3. As shown in FIG. 7, the yarn 24 is planted into the backing material 10 after the wire 32 has been moved to a position to escape from the loop formed at Step 3. In this way, the wire which has formed the preceding loop can hold its fold in place in the PVC until the other wire is poised and ready to plant the yarn 24 at the other side of the well 20. Before the other wire creates any tension on the yarn, the first one escapes from where the next loop is to be formed and slack is created in the yarn so that the preceding fold is not pulled out of the PVC. This procedure insures that the folds remain embedded in the PVC without sacrificing operational speed.

Now, referring to FIG. 8, as the wire 34 holds the strands of yarn 24 in place to prevent them from pulling out of the PVC, the wire 32 is moved to the right into the positon shown in FIG. 8, where it is poised and ready to push the strands of yarn 24 into the PVC at Step 4 at the right-hand side of the well 20. Before the layers of backing material 10 are advanced again, the wire 34 moves horizontally toward the right-hand side of the well 20 and then upwardly to the position shown in FIG. 9 to be out of the way of the wire 32 and the next loop. Then, the comb 44 clamps the strands of yarn 24 and drops them a short distance'to create the slack shown in FIG. 10.

The wire 32 is moved straight down to the position shown in FIG. 10 and the layers of backing material are advanced to the next step. The wire 32 is then moved to the right to plant the strands of yarn 24 into the PVC at the right-hand side of the well 20 at Step 4, as shown in FIG. 1 1. While the wire 32 holds the strands of yarn 24 in place, the wire 34 moves toward the position shown in FIG. 12. After the wire 34 reaches that position, the wires 32, 34, are in the same positions shown in FIG. 4. Thus, one cycle has been completed of folding and planting the yarn 24 first in the PVC on one side of the well 20 and then in the PVC on the other side of the well 20 to create the accordion-like chains of yarn 20 between the layers of backing material 10.

As shown in FIG. 1, the electromagnets 64 can be positioned behind the vertical portions of the guides 18 on both sides of the well 20 at the exact places where the wires 32, 34, plant the strands of yarn. The electromagnets 64 can be activated during each planting step (see FIGS. 7 and 11) to insure that the yarn is planted at the same place each time.

The means for moving the wires 32, 34, along the paths shown in FIGS. 4-12 will now be described in detail. As shown in FIG. 13, which is a top view of the moving mechanism on one side of the machine, the wires 32, 34, are moved by the reversible stepping motors 66, 68, that operate to rotate the wire holders 70, 72 (shown in detail in FIG. 25). For this embodiment of the invention, the portions of the wires 32, 34, that are connected to the wire holders 70, 72, are moved independently along separate, concentric, orbital paths instead of the linear paths described in conjunction with FIGS. 4-12.

The translation from orbital to linear movement is accomplished by means of a cam profile plate 74 located between the wire holders 70, 72, and the well 20 (see FIG. 13). The cam profile plate 74 includes a cam surface 76 that engages and guides the wires 32, 34, and defines the linear paths along which the wires move (see FIGS. 14 and 15). The plate 74 is adjustably movable relative to the well 20 so that the wires 32, 34, can be precisely aligned to move along the linear paths described above. I g

The movement of the wires 32, 34, along their orbital paths in conjunction with their corresponding linear movement for one cycle of the folding and planting operation is shown schematically in FIGS. 16-24.

In FIG. 16, the portions of the wires 32, 34, shown within the cam surface 76 of the cam profile plate 74 are in the positions shown in FIG. 4. The portions of the wires 32, 34, shown outside the cam surface 76 are the portions connected to the wire holders 70, 72, respectively, and are shown at their respective positions along their concentric orbital paths 78, 80.

In order to move the wire 32 to the position shown in FIG. 17, the wire holder is rotated to move the wire 32 along the orbital path 78 in the direction of the arrow shown in FIG. 17. When this happens the cam surface 76 guides the wire 32 linearly to the position shown in FIG. 17. The wires 32, 34, are now in the positions shown in FIG. 5.

The wire 34 is then moved to the position shown in FIG. 18. This is done by rotating the wire holder 72. which moves the wire 34 along its orbital path 80 in the direction of the arrow shown in FIG. 18. In order to move the wire 34 straight down instead of around the profile of the cam surface 76, a cam plate slide 82 is moved into the position shown in FIG. 18 by means of the solenoid 84 moving the plunger 86 (see FIG. 13). A second slide 88 and plunger 92, moved by the solenoid 90, are provided to function in a similar manner in the other side of the cam surface 76 and will be described in conjunction with FIGS. 22 and 23.

The cam profile plate 74 and the slides 82, 88, are shown in detail in FIGS. 14 and 15, where the wires 32, 34, are in the positions shown in FIG. 18. The solenoids 84, 90, are synchronized with the stepping motors that move the wire holders 70, 72, to function as described. The slides 82, 88, move within the groove 93 that is located within the cam profile plate 72, as shown best in FIG. 15.

The wire 34 is then moved to the position shown in FIG. 19 to plant the yarn at the left-hand side of the well 20, as shown in FIG. 7. This is done by rotating the wire holder 72, which moves the wire 34 along its orbi tal path 80 in the direction of the arrow shown in FIG. 19. As this happens the slide 82 is withdrawn from within the cam surface 76 by the solenoid 84 and moved to the right in FIG. 19.

The wire 32 is then moved to the position shown in FIG. 20 by rotating the wire holder 70, which moves the wire 32 along its orbital path 78 in the direction of the arrow shown in FIG. 20, the wires 32, 34, now being in the position shown in FIG. 8. The wire holder 72 then moves the wire 34 to the position shown in FIG. 21, rotating in the direction of the arrow shown in FIG. 21.

The slide 88 is moved into the position shown in FIG. 22 and the wire 32 is moved straight down by the wire holder 70 similar to the way the wire 34 was moved down to the position shown in FIG. 18. The wires 32, 34, are now in the position shown in FIG. 10. The wire 32 is then moved to the right to the position shown in FIG. 23 to plant the yarn at the right-hand side of the well 20 as shown in FIG. 11. The slide 88 is then withdrawn from within the cam surface 76 by means of the solenoid 90. The wire 34 is then moved to the position shown in FIG. 24. The wires 32, 34, are then in the same positions shown in FIG. 16 and one cycle of the folding and planting operation has been completed.

Alternative to the operation just described, the slides 82, 88, can be controlled by appropriately designed and known solenoids or other moving means to move each of the slides into a third position. This third position would be a short distance inside the vertical dimension of the cam surface 76 so that instead of the wires 32, 34, moving directly to the positions shown in FIGS. 17 and 21, respectively, they will engage a slide and move vertically without engaging the cam surface 76. In this way, the wires will move vertically at a short distance from the cam surface 76 and the PVC coating so that if there are any irregularities in the PVC coating the wires will not touch the PVC while they are moving.

After the wires 32, 34, move to their vertical positions. the slides 88, 82, will be moved to their positions outside the area of the cam surface 76, so that the slides will not interfere with the next planting step. When the slides are so moved, the wires will move automatically to the positions shown in FIGS. 17 and 21 because of the tension in the wires created by the springs described below. The wires can be positioned, as shown in FIGS. 5 and 9, so that at the limit of their vertical movement they will be above the horizontal portion of the guides 18. Thus. when the slides are moved out of the cam surface 76, the wires will not touch the PVC when they move to engage the cam surface 76.

FIG. 25 shows in detail the mechanism used to move the wires 32, 34, and is a section view of the hub 94 shown in FIG. 13, along with other components of the mechanism.

The hub 94 includes a housing 95 in which the annular wire holders 70, 72 are mounted for rotation. The wire holder in nested for independent rotation within the wire holder 72. The wire holder 70 has a chamber 96 extending axially through it, where the wire 32 is connected, but the chamber 96 is off center so that when the wire holder 70 rotates the portion of the wire 32 in the wire holder 70 will move along the orbital path 78.

The wire holder 72 is cylindrical in shape and designed to fit over the wire holder 70. The bearings 97, 98, are disposed between the wire holders 70, 72, so that they can rotate independent of each other. The bearings 98 are prevented from moving laterally to the left by the retainer plate 102. The wire holder 72 is. in turn, rotatably connected to the inner surface of the housing through the bearings 100, which are held in place by the spacer 104 and the collar 105. The bearings 97, 98 and 100, are all combined roller and thrust bearings to effectively combat the tendency of the wire holders on opposite sides of the well 20 to move toward each other in addition to allowing their rotational movement. The wire holder 72 includes the chamber 106 extending axially through it, where the wire 34 is connected. Thus, as the wire holder 72 rotates, the portion of the wire 34 in the wire holder 72 will move along the orbital path 80.

The wires 32, 34, are tensioned between their respective pairs of wire holders by a helical spring 108 located in the chambers 96, 106, preferably on one side of the machine. The ends of the wires 32, 34, are connected to the balls 110 that are clamped onto the ends of each wire, the balls 110 being held in place on the outer edge of the sliders 112. The connection between the wires and the balls is such that the wires can easily be replaced when needed. With this type of arrangement, the combined orbital and linear movement of the wires 32, 34, is made possible because when the length of the wires between the cam surface and their holders tends to increase due to the difference in shape between the cam surface and the orbital paths of the wire ends, the sliders 112 will move inwardly causing the springs 108 to compress. In addition, when the length tends to decrease the springs 108 will cause the sliders 112 to move outwardly and maintain a predetermined minimum tension in the wires. An opening 113 is provided in the wire holder 72 so that the wire 34 can easily be replaced.

The wire holder 70, 72, are rotated by a pair of conventional, reversible. stepping motors 66, 68. The stepping motor 66 drives the gear 118 which in turn drives the gear 120 that is connected to the wire holder 70, and the stepping motor 68 drives the gear 122 which drives the gear 124 that is connected to the wire holder 72. For the arrangement shown in H0. 25, the gear 120 includes an opening 126 so that the wire 34 can be replaced. The stepping motors 66, 68, are programmed in a known way to rotate the wire holders 70, 72, in the sequence described in conjunction with FIGS. 1624. Although the gears 118, 122, are shown in FIG. 25 to be approximately one-half the diameter of the gears 120, 124, other suitable ratios can be used. The stepping motors 66, 68, are synchronized with each other, with the solenoids 84, 90, and with the stepping motors that are used to advance the layers of backing material 10 to accomplish the results discussed above.

Thus, there is provided in accordance with the invention a mechanism that is capable of folding and planting strands of yarn in the PVC coating on advancing layers of backing material much more quickly and efficiently than prior art devices. The embodiment of the invention described above is intended to be merely exemplary, and those skilled in the art will be able to make modifications and variations to it without departing from the spirit and scope of the appended claims. All such modifications and variations are contemplated as falling within the scope of the claims.

I claim:

1. A mechanism for engaging a plurality of strands of flexible material and folding each strand into a series of loops, comprising a pair of flexible elongated members, tensioning and moving means for tensioning said elongated members across said strands and moving said elongated members along predetermined paths so that said members will alternately engage said strands and urge them back and forth to form said series of loops.

2. The mechanism in claim 1, wherein said elongated members are wire-like members.

3. The mechanism in claim 1, wherein the tensioning and moving means includes holding means for holding the elongated members in tension connected to the elongated members outwardly of each side of the area covered by the strands.

4. The mechanism in claim 3, wherein the holding means includes orbital motion means for enabling portions of the elongated members located outwardly of the area covered by the strands to be moved in orbital paths.

5. The mechanism in claim 4, wherein said orbital motion means includes means for enabling said outwardly located portions of one of the elongated members to be moved in an orbital path concentric with the path of the outwardly located portions of the other elongated member.

6. The mechanism in claim 3, wherein said tensioning and moving means includes a pair of movable members disposed on each side of the area covered by the strands, the movable members that comprise each pair being independently movable relative to each other, said elongated members being connected to and extending between said pairs of movable members.

7. The mechanism in claim 6, wherein said movable members are rotatably movable so that the portions of said elongated members that are connected to said movable members can be moved along orbital paths.

8. The mechanism in claim 6, wherein the movable members that comprise each of said pairs are coaxial.

9. The mechanism in claim 8, wherein the movable members that comprise each of said pairs are nested one in another.

10. The mechanism in claim 9, wherein said movable members include bearing means therebetween.

11.The mechanism in claim 3, wherein said holding means includes spring means connected to at least one end of each elongated member so that the portion of said elongated members extending between said holding means can vary in length and be maintained at a minimum tension.

12. The mechanism in claim 11, wherein said spring means includes a coil spring.

13. The mechanism in claim 12, wherein the holding means includes a chamber at each end of an elongated member to which spring means is connected, said spring means being located in said chamber and being in a state of compression.

14. The mechanism in claim 13, wherein a slider is connected to the end of each elongated member connected to spring means, each slider being slidingly movable in one of said chambers and engaging the outer end of the coil spring located in said chamber.

15. The mechanism in claim 3, wherein said tensioning and moving means includes a reversible stepping motor on each side of said area for moving said movable members.

16. The mechanism in claim 4, and further including translating means for translating the orbital movement of said outwardly located portions of said elongated members into predetermined folding movement in the portion of each of said elongated members that engages said strands.

17. The mechanism in claim 16, wherein said predetermined folding movement includes linear movement.

18. The mechanism in claim 17, wherein said translating means includes cam surfaces located outwardly of each side of the area covered by said strands, said cam surfaces being shaped and dimensioned to engage and guide said elongated members along paths to accomplish said predetermined folding movement, said portions of said elongated members being parallel to one another during said movement.

19. The mechanism in claim 18, wherein said translating means includes cam means on each side of the area covered by the strands including guiding portions defined by said cam surfaces.

20. The mechanism in claim 19, wherein each of said guiding portions is an opening generally rectangular in shape.

21. The mechanism in claim 19, wherein said cam surfaces are totally within the orbital path of each elongated member in the plane perpendicular to said elongated members.

22. The mechanism in claim 19, wherein each of said cam means includes a pair of movable cam means for moving between advanced and retracted positions for selectively engaging and guiding said elongated members along different paths in said retracted and advanced positions.

23. The mechanism in claim 22, wherein the movable cam means in each pair respectively define opposing sides of said cam surfaces.

24. The mechanism in claim 23, wherein each of said movable cam means includes a pair of plates slidingly movable relative to said cam plate means.

25. The mechanism in claim 24, wherein each of said movable cam means includes drive means for moving said plates between said retracted and advanced positions.

26. A mechanism for engaging a plurality of strands of flexible material and folding each strand into a series of loops, comprising a pair of elongated members, holding means for holding said elongated members across the area covered by said strands, said holding means being connected to the elongated members outwardly of each side of the area covered by said strands, and moving means for moving said elongated members along predetermined paths so that said members will alternately engage said strands and urge them back and forth to form said series of loops.

27. The mechanism in claim 26, wherein the holding means are rotatably movable so that the portions of the elongated members connected to the holding means can be moved along orbital paths.

28. The mechanism in claim 27, wherein said connected portions of the elongated members are rotatably movable aboutr a common axis.

29. The mechanism in claim 28, wherein the connected portions of one elongated member are a different distance from the common axis than the connected portions of the other elongated member.

30. The mechanism in claim 26, wherein said holding means holds said elongated members in tension therebetween.

31. The mechanism in claim 30, wherein spring means is connected to at least one end of each elongated member so that the portion of each elongated member between the holding means can vary in length and maintain a minimum tension therein.

32. The mechanism in claim 31, and further including translating means for translating the orbital movement of the elongated members into predetermined folding movement in the portions of the elongated members that engage the strands.

33. The mechanism in claim 32, wherein the translating means includes cam surfaces located outwardly of each side of the area covered by the strands, said cam surfaces being shaped and dimensioned to engage and guide the elongated members along said predetermined paths.

34. The mechanism in claim 33, wherein the translating means includes cam means on each side of the area covered by the strands including guiding portions defined by said cam surfaces.

35. The mechanism in claim 34, wherein the cam means further includes movable cam means for selectively engaging and guiding the elongated members along paths different from paths defined by the guiding portions during selected portions of each yarn folding cycle.

36. The mechanism in claim 26, wherein said moving means includes reversible stepping motors operatively connected to the holding means.

37. The mechanism in claim 26, wherein the holding means includes a pair of movable members disposed on each side of the area covered by the strands, the movable members that comprise each pair being independently movable relative to each other.

38. The mechanism in claim 37, wherein the movable members are rotatably movable about a common axis. 

1. A MECHANISM FOR ENGAGING A PLURALITY OF STRANDS OF FLEXIBLE MATERIAL AND FOLDING EACH STRAND INTO A SERIES OF LOOPS, COMPRISING A PAIR OF FLEXIBLE ELONGATED MEMBERS, TENSIONING AND MOVING MEANS FOR TENSIONING SAID ELONGATED MEMBERS ACROSS SAID STRANDS AND MOVING SAID ELONGATED MEMBERS ALONG PREDETERMINED PATHS SO THAT SAID MEMBERS WILL ALTERNATELY ENGAGE SAID STRANDS AND URGE THEM BACK AND FORTH TO FORM SAID SERIES OF LOOPS.
 2. The mechanism in claim 1, wherein said elongated members are wire-like members.
 3. The mechanism in claim 1, wherein the tensioning and moving means includes holding means for holding the elongated members in tension connected to the elongated members outwardly of each side of the area covered by the strands.
 4. The mechanism in claim 3, wherein the holding means includes orbital motion means for enabling portions of the elongated members located outwardly of the area covered by the strands to be moved in orbital paths.
 5. The mechanism in claim 4, wherein said orbital motion means includes means for enabling said outwardly located portions of one of the elongated members to be moved in an orbital path concentric with the path of the outwardly located portions of the other elongated member.
 6. The mechanism in claim 3, wherein said tensioning and moving means includes a pair of movable members disposed on each side of the area covered by the strands, the movable members that comprise each pair being independently movable relative to each other, saId elongated members being connected to and extending between said pairs of movable members.
 7. The mechanism in claim 6, wherein said movable members are rotatably movable so that the portions of said elongated members that are connected to said movable members can be moved along orbital paths.
 8. The mechanism in claim 6, wherein the movable members that comprise each of said pairs are coaxial.
 9. The mechanism in claim 8, wherein the movable members that comprise each of said pairs are nested one in another.
 10. The mechanism in claim 9, wherein said movable members include bearing means therebetween.
 11. The mechanism in claim 3, wherein said holding means includes spring means connected to at least one end of each elongated member so that the portion of said elongated members extending between said holding means can vary in length and be maintained at a minimum tension.
 12. The mechanism in claim 11, wherein said spring means includes a coil spring.
 13. The mechanism in claim 12, wherein the holding means includes a chamber at each end of an elongated member to which spring means is connected, said spring means being located in said chamber and being in a state of compression.
 14. The mechanism in claim 13, wherein a slider is connected to the end of each elongated member connected to spring means, each slider being slidingly movable in one of said chambers and engaging the outer end of the coil spring located in said chamber.
 15. The mechanism in claim 3, wherein said tensioning and moving means includes a reversible stepping motor on each side of said area for moving said movable members.
 16. The mechanism in claim 4, and further including translating means for translating the orbital movement of said outwardly located portions of said elongated members into predetermined folding movement in the portion of each of said elongated members that engages said strands.
 17. The mechanism in claim 16, wherein said predetermined folding movement includes linear movement.
 18. The mechanism in claim 17, wherein said translating means includes cam surfaces located outwardly of each side of the area covered by said strands, said cam surfaces being shaped and dimensioned to engage and guide said elongated members along paths to accomplish said predetermined folding movement, said portions of said elongated members being parallel to one another during said movement.
 19. The mechanism in claim 18, wherein said translating means includes cam means on each side of the area covered by the strands including guiding portions defined by said cam surfaces.
 20. The mechanism in claim 19, wherein each of said guiding portions is an opening generally rectangular in shape.
 21. The mechanism in claim 19, wherein said cam surfaces are totally within the orbital path of each elongated member in the plane perpendicular to said elongated members.
 22. The mechanism in claim 19, wherein each of said cam means includes a pair of movable cam means for moving between advanced and retracted positions for selectively engaging and guiding said elongated members along different paths in said retracted and advanced positions.
 23. The mechanism in claim 22, wherein the movable cam means in each pair respectively define opposing sides of said cam surfaces.
 24. The mechanism in claim 23, wherein each of said movable cam means includes a pair of plates slidingly movable relative to said cam plate means.
 25. The mechanism in claim 24, wherein each of said movable cam means includes drive means for moving said plates between said retracted and advanced positions.
 26. A mechanism for engaging a plurality of strands of flexible material and folding each strand into a series of loops, comprising a pair of elongated members, holding means for holding said elongated members across the area covered by said strands, said holding means being connected to the elongated members outwardly of each side of the area covered by said strands, aNd moving means for moving said elongated members along predetermined paths so that said members will alternately engage said strands and urge them back and forth to form said series of loops.
 27. The mechanism in claim 26, wherein the holding means are rotatably movable so that the portions of the elongated members connected to the holding means can be moved along orbital paths.
 28. The mechanism in claim 27, wherein said connected portions of the elongated members are rotatably movable about a common axis.
 29. The mechanism in claim 28, wherein the connected portions of one elongated member are a different distance from the common axis than the connected portions of the other elongated member.
 30. The mechanism in claim 26, wherein said holding means holds said elongated members in tension therebetween.
 31. The mechanism in claim 30, wherein spring means is connected to at least one end of each elongated member so that the portion of each elongated member between the holding means can vary in length and maintain a minimum tension therein.
 32. The mechanism in claim 31, and further including translating means for translating the orbital movement of the elongated members into predetermined folding movement in the portions of the elongated members that engage the strands.
 33. The mechanism in claim 32, wherein the translating means includes cam surfaces located outwardly of each side of the area covered by the strands, said cam surfaces being shaped and dimensioned to engage and guide the elongated members along said predetermined paths.
 34. The mechanism in claim 33, wherein the translating means includes cam means on each side of the area covered by the strands including guiding portions defined by said cam surfaces.
 35. The mechanism in claim 34, wherein the cam means further includes movable cam means for selectively engaging and guiding the elongated members along paths different from paths defined by the guiding portions during selected portions of each yarn folding cycle.
 36. The mechanism in claim 26, wherein said moving means includes reversible stepping motors operatively connected to the holding means.
 37. The mechanism in claim 26, wherein the holding means includes a pair of movable members disposed on each side of the area covered by the strands, the movable members that comprise each pair being independently movable relative to each other.
 38. The mechanism in claim 37, wherein the movable members are rotatably movable about a common axis. 